Short bowden extruder & E3D v6 bracket for Velleman K8200 / 3Drag by akkenoth

Last crawled date: 3 years, 1 month ago

Description
An improved bracket for Velleman K8200 / 3Drag to hold E3D v6 hotend (or clones) and generic MK8-based bowden extruder.
Based on Arron_mollet22's idea, designed from scratch in 123D Design.
Use at your own risk. I'm not responsible for misprints, fried stepsticks, your printer catching fire or attacking you. Though this part is working for me.
Improvements
Main improvements (compared to original model)
wider parts (8 vs 6 mm for main structures)
more accurate dimensions (based on technical drawings of things to be used)
better grip on printer's aluminium extrusion/profile
added screw for locking hotend in place
designed to print without supports and with minimal overhangs
Vitamins needed
4x M4x25 screw (for assembling the bracket)
2x M4x15 screw (for mounting stepper motor bracket)
1x M4x60 screw (for locking the hotend)
7x M4 washer
7x M4 nut
And, of course, you'll need extruder, hotend and a piece of PTFE tubing (about 5cm).
Build notes
Push nuts into plastic gently - I've used a vise
Don't overtighten the screws
Use washers
Measure twice (or 4 times), cut once
1mm too much of the tubing won't hurt, it can be squeezed a bit
Follow E3D's notes on building the extruder
My chinese V6 copy required drilling the pneumatic lock for the tubing to go inside
Mount the hotend's fan so that it blows upwards not downwards or it will affect the prints
Heater cardridge's and thermistor's cables were long enough so I didn't use original ribbon cable
My extruder's spring was too hard so I've removed the additional nut from spring's screw
Usage notes
I recommend switching extruder motor driver to DRV8825
Increase extruder motor's current to 1.4-1.6A or it will skip
I've lost about 2cm of Y-axis movement - might have to reposition the bed or the vertical frame
Use PID auto-tuning
Add a cover against cold air blows (e.g. pieces of cardboard)
Print settings (for PLA)
STEPS_PER_UNIT or STEPS_PER_MM: 100 for original stepstick, 200 for DRV8825
Slic3r Print settings: mostly default Slic3r ones, lowered the speeds slightly
Slic3r Filament settings:
Diameter: 1.75
Extrusion multiplier: 1
Extruder temperature: 195->190 (depends on your material ofc)
Heatbed temperature: 60
Cooling: yes (adjust to your needs)

Slic3r Printer settings:
Extruder nozzle diameter: 0.4

Results
After dealing with problematic heatbed and adding cardboard covers for the printer, it prints nicely.
I've used glass on original heatbed (with additional cardboard insulation below) and stick glue. 0.3 layers, 200% width for first layer.
Still requires some calibration, 3DBenchy pictures included.